Many of the no-nail, thumb & forefinger
openers in my Victorinox collection . . .Bottom R->L:
WorkChamp liner lock ; Skipper ; Outrider ; Rucksack ; Helmsman ; Nomad ; Huntsman ; Climber
Top R->L:
Tourist ; Evowood 14 ; Bantam ; Evogrip s17 ; Evogrip s18 ; Evogrip 14
Seems to be a question of enough blade rising above the tools on either side of the blade, AND exposing the nail nick, which provides traction.
Perhaps a small issue for many, or most, but those of us with brittle, not too thick nails really appreciate pinch opening on a pocket knife blade.
My nails are very fast-growing, which helps. Getting at the awl, which I do use quite a bit, can be a real nail-splitter. Not to mention the hook on
my Huntsman, which is blocked by the split-ring (unless someone knows something I don't know about opening up the Huntsman hook).
The One-hand models are all liner locks, and I am less likely to casually carry any locking blade, so I do very much appreciate these pinchies.
Most of the side-lock mechanisms on the 111mm have been removed, so they are legal carry even in town. (10cm length limit.)